Problem: Simplify the following expression: $t = \dfrac{5z + 9}{z} \div \dfrac{1}{9}$
Dividing by a number is the same as multiplying by its inverse. $t = \dfrac{5z + 9}{z} \times \dfrac{9}{1}$ When multiplying fractions, we multiply the numerators and the denominators. $t = \dfrac{(5z + 9) \times 9} {(z) \times 1}$ $t = \dfrac{45z + 81}{z}$